We have demonstrated that a structured plasmonic channel, with high ratio of the carrier concentration of the stripes can provide the momentum change in the incident photons, in turn, these photons can be coupled to the surface plasmons in the two-dimensional channel of confined electron gas formed at the hetero-interface of a GaAs/AlGaAs HEMT device. The propagation of the plasma wave along the channel generates a voltage difference between the drain and the source of the device that can be electrically measured. Based on the hydrodynamic model of this short channel HEMT device, this voltage is proportional to the quality factor of the resonator and generates resonant peaks at the harmonics of the input excitation, making it a promising candidate for single-band detection. These devices can be used in THz detectors, since the resonant frequency of the plasmons in the channel lies within the range of THz. Terahertz is the frontier range in electronics and optoelectronics for applications in various areas such as radio astronomy, wireless communications, biotechnology, medicine, etc. In HEMT devices, the two dimensional electron gas with the infrequent collisions with impurities and lattice vibrations provides a high quality factor resonant cavity for plasma waves to generate.